Vehicles such as fire engines, pumpers, trucks, and other vehicles that pump water or other fluids use different controls to actuate valves in piping systems. Additionally, stationary and mobile pumping systems for liquids, gases, vapors, slurries, etc., also use valve control systems. Valve control devices include linear actuation control rods, angular displacement handles, electric actuators, pneumatic actuators, hydraulic actuators, and valve control handwheels. For example, a valve control handwheel may be attached by linkage, e.g., a worm gear drive or other linkage, to a valve. The valve control handwheel is used to start, stop, reduce, increase, and regulate the flow of liquids, gases, vapors, slurries, etc. through the valve. It can also regulate piping system pressure. Rotation of the valve control handwheel turns the linkage and rotates a ball, plug, or butterfly of the valve. The valve control handwheel controls the flow of liquid through the valve, whether partially or entirely opened or closed.
Several problems exist with valve control handwheels. Many valve control handwheels lack a position indicator for the valve that they control. In the absence of a valve indicator, the operator must estimate the position of the valve. Limited types of indicators are available for valve control handwheels. For example, valve control handwheels may have analog dial indicators centrally located on the handwheel. Analog indicators rely on gravity to keep a dial face stationary relative to the rotating handwheel as an indicator needle moves adjacent the dial face. This design works only if the analog indicator is mounted vertically on a surface so that its dial face is also vertical. It will not work properly if mounted on a surface that is horizontal or insufficiently inclined because gravity will be less effective or ineffective in maintaining the dial face in a relatively stationary position. Consequently, this will nullify or minimize the accuracy of the analog dial indicator. To overcome this limitation, some analog valve position indicators include a mechanical protrusion that contacts a stationary panel and secures the dial face in a stationary position relative to rotation of the valve control handwheel and as its indicator needle moves relative to the stationary dial face. While the mechanical mechanism prevents rotation of the dial face, its allows for moisture and other potentially corrosive debris to enter the valve position indicator and foul its works which, over time, renders the indicator inaccurate and then completely unusable.